A number of liquid-crystalline side-chain polymers are already known. Thus, for example, German Offenlegungsschrift 2,944,591 and European Patent Specification 0,060,335 describe organopolysiloxanes, and German Offenlegungsschrift 2,831,909 and Springer and Weigelt, Makromol. Chem. 184 (1983) 1489, describe polymethacrylates possessing mesogenic side groups.
The common feature of these known side-chain polymers is that their mesogenic groups are bonded to the polymer backbone, if appropriate via a spacer, at the 4-position in the direction of the longitudinal molecular axis, and hence analogously to the customary wing groups. Such polymer materials frequently have nematic phases at temperatures above 100.degree. C. In many cases, such materials also exhibit crystalline behavior, associated with the lack of mesomorphic properties.
To date, only comparatively small lateral substituents have been considered to be compatible with the occurrence of liquid-crystalline properties (cf. Gray in: The Molecular Physics of Liquid Crystals (editors G. R. Luckhurst and G. W. Gray), London-New York-San Francisco 1979, page 1).